Thousands of children with elevated blood lead levels (EBLL) may be undiagnosed, according to a new study.
Researchers found large gaps between the number of children projected to have EBLL and those reported to health officials.
“While we find no evidence of under-ascertainment in a number of states, the majority appear to successfully identify fewer than half of their children with EBLL,” authors wrote in the study “Assessing Child Lead Poisoning Case Ascertainment in the U.S., 1999-2010” (Roberts EM, et al. Pediatrics. April 27, 2017, https://doi.org/10.1542/peds.2016-4266).
Lead exposure has been associated with health, learning and behavior problems, and no amount is considered safe. The authors looked at the prevalence of EBLL among 1- to 5-year-olds in each state from 1999-2010, which was made possible by using new statistical models with National Health and Nutrition Examination Survey data.
As part of the Centers for Disease Control and Prevention’s (CDC’s) Childhood Lead Poisoning Prevention Program, 38 states and Washington, D.C., reported EBLL cases of 10 micrograms per deciliter (µg/dL) or higher during the study years. (The reporting threshold has since been lowered to 5 µg/dL).
The CDC received reports of 606,709 cases of EBLL, but statistical models show the case count was closer to 1.2 million. The authors attributed just over half to cases being missed and the remainder to states not reporting in some years.
Looking only at states and years with complete reports, one-third of cases went undiagnosed, according to the study. In the Northeast and Midwest, 99.5% and 94.3% of expected cases respectively were reported compared to 25.3% in the South and 21.8% in the West.
In a 2016 policy Prevention of Childhood Lead Toxicity, the Academy recommends pediatricians test children for EBLL based on federal, state and local guidelines.
However, the findings of the study show “clinicians are frequently unaware of the guidelines, and — if they are aware — then lack of enforcement undermines any effect they may have on clinician behavior,” authors wrote.
They recommend public health officials better communicate guidelines with providers and clinicians be more aggressive in testing.